The present invention relates to a process for the alcoholysis of carbon tetrachloride (CCl.sub.4) in the presence of an aqueous solution of a metal halide.
The reaction for the alcoholysis of CCl.sub.4 according to the equation: EQU 4ROH+CCl.sub.4 .fwdarw.4RCl+2H.sub.2 O+CO.sub.2 (I)
leads to alkyl halides RCl and allows the CCl.sub.4 to be upgraded. CCl.sub.4 is inevitably produced in the manufacture of higher chloromethanes, but the use of CCl.sub.4 as a commodity chemical will likely be banned at the end of this century since it is highly suspected of being responsible for the decrease of the ozone layer in the stratosphere.
French patent 793,731 describes a process for the alcoholysis of CCl.sub.4 which consists in passing a gaseous mixture consisting of an alcohol (ethanol or methanol) and CCl.sub.4 over solid substances having an active surface such as active charcoal or silica gel. These substances may optionally be charged with activating substances such as zinc chloride (ZnCl.sub.2) or phosphorus compounds.
European Patent Application EP 435,210 describes a process for the preparation of CH.sub.3 Cl which consists in passing a gaseous mixture consisting of CH.sub.3 OH and CCl.sub.4 over a solid catalytic bed of active charcoal containing an oxide or a halide of an element chosen from groups I B, II A, II B, VI B, VII B and VIII of the Periodic Table of the Elements. The reaction takes place at temperatures between 150.degree. C. and 250.degree. C. at pressures equal to about 10 kg/cm.sup.2.
German patent DE 4,131,213 describes a process for the alcoholysis of CCl.sub.4 which consists in reacting, in the gaseous phase, CCl.sub.4 with an aliphatic alcohol having from 1 to 10 carbon atoms, in the presence of a solid catalyst which consists of silica and/or activated alumina.